• 미생물학회지
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• 제44권1호
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• pp.43-48
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• 2008

정도관리는 분석 결과의 신뢰성을 높이기 위해 필수적인 과정이며, 이를 위해서는 일정한 농도의 표준시료가 필요하다. 본 연구에서는 정도관리의 정략분석을 위해 실온에서도 일정시간 개체수가 유지되는 미생물 정도관리용 표준시료를 제작하였다. 대장균으로 조제한 미생물 시료에 세포 분열을 억제하기 위해 nalidixic acid ($100\;{\mu}g/ml$)와 cephalexin ($50\;{\mu}g/ml$)을 첨가하였다. 이후 12시간 간격으로 acridine orange로 염색 후 현미경으로 계수하는 방법과 한천 배지에 배양하여 집락을 계수하는 평판집락계수법으로 개체수 변화를 측정하였다. 현미경 계수 결과 초기간이 $3.7{\times}10^5\;cells/ml$이었을 때 대장균의 개체수는 48시간 동안 $3.5{\sim}4.2{\times}10^5\;cells/ml$의 범위를 보였고, 평판집락법 결과 초기값이 $1.2{\times}10^4\;CFU/ml$ 이었을 경우에는 $1.0{\sim}1.2{\times}10^4\;CFU/ml$로 조사되어 냉장 및 냉동의 필요 없이 실온에서도 48시간 동안 개체수가 비교적 안정적으로 유지되는 미생물 표준시료를 제작할 수 있었다. 따라서 본 연구에서 제작된 표준시료는 현재 상업적으로 판매되고 있는 표준균주 제품과 함께 정도관리의 정략분석을 위해 사용될 수 있을 것이다.

• 한국수산과학회지
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• 제19권1호
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• pp.20-26
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• 1986

Very little information is available in the literature on storage of fish sauce. Therefore, microbiological and chemical chracteristics during storage and quality of fish sauce were investigated and discussed to present data about the optimum storage condition. The chopped sardine meat was mixed with equal amount of water and $9\%$(w/w) of $75\%$ vital wheat gluten and then hydrolyzed by addition of commercial proteolytic enzymes such as bromelain, papaya protease, ficin and a enzyme mixture (Pacific Chem. Co.) for 4 hours at $52.5^{\circ}C$. The reaction mixture was heated for 30 min at $100^{\circ}C$ for enzyme inactivation, pasteurization and color development and then centrifuged for 20 min at 4,000 rpm. Table salt and benzoic acid were added for bacteriostatic effect and stored for 80 days at $15{\pm}1^{\circ}C$ and $30{\pm}1^{\circ}C$. The results were summarized as follows: 1. The amount of amino-nitrogen and pH of fish sauce were almost unchanged during storage. 2. Mininum concentration of salt for bacteriostatic activity was $9\%$(w/w) regardless of addition of benzoic acid. 3. the yields of amino-nitrogen were $63.1\%$ for the hydrolysate prepared without enzyme, $79.7\%$ for that with bromelain, $69.9\%$ with ficin, $74.3\%$ with papaya pretense, and $78.1\%$ with enzyme mixture, respectively. 4. The contents of amino-nitrogen were $4510.0mg\%$ on the dry basis for the product prepared by autolysis, $5483.2mg\%$ for that prepared with bromelain, $5305.7mg\%$ with ficin, $4994.1mg\%$ with papaya protease and $5582.3mg\%$ with the enzyme mixture, respectively. 5. The contents of crude protein were $51.35\%$ on the dry basis for the product prepared by autolysis and 55 to $59\%$ for prepared with commercial enzymes. 6. The hydrolysate prepared with the enzyme mixture revealed a little stronger meaty taste than any other products. 7. The level of crude protein in residues was still high ($69.5{\sim}77.2\%$ on the dry basis) and might be originated from the added vital wheat gluten.

• Journal of Veterinary Science
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• 제22권6호
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• pp.41.1-41.14
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• 2021

Background: Our previously prepared ceftiofur (CEF) hydrochloride oily suspension shows potential wide applications for controlling swine Streptococcus suis infections, while the irrational dose has not been formulated. Objectives: The rational dose regimens of CEF oily suspension against S. suis were systematically studied using a pharmacokinetic-pharmacodynamic model method. Methods: The healthy and infected pigs were intramuscularly administered CEF hydrochloride oily suspension at a single dose of 5 mg/kg, and then the plasma and pulmonary epithelial lining fluid (PELF) were collected at different times. The minimum inhibitory concentration (MIC), minimal bactericidal concentration, mutant prevention concentration (MPC), post-antibiotic effect (PAE), and time-killing curves were determined. Subsequently, the area under the curve by the MIC (AUC_0-24h/MIC) values of desfuroylceftiofur (DFC) in the PELF was obtained by integrating in vivo pharmacokinetic data of the infected pigs and ex vivo pharmacodynamic data using the sigmoid E_max (Hill) equation. The dose was calculated based on the AUC_0-24h/MIC values for bacteriostatic action, bactericidal action, and bacterial elimination. Results: The peak concentration, the area under the concentration-time curve, and the time to peak for PELF's DFC were 24.76 ± 0.92 ㎍/mL, 811.99 ± 54.70 ㎍·h/mL, and 8.00 h in healthy pigs, and 33.04 ± 0.99 ㎍/mL, 735.85 ± 26.20 ㎍·h/mL, and 8.00 h in infected pigs, respectively. The MIC of PELF's DFC against S. suis strain was 0.25 ㎍/mL. There was strong concentration-dependent activity as determined by MPC, PAE, and the time-killing curves. The AUC_0-24h/MIC values of PELF's DFC for bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria were 6.54 h, 9.69 h, and 11.49 h, respectively. Thus, a dosage regimen of 1.94 mg/kg every 72 h could be sufficient to reach bactericidal activity. Conclusions: A rational dosage regimen was recommended, and it could assist in increasing the treatment effectiveness of CEF hydrochloride oily suspension against S. Suis infections.

• Advances in Traditional Medicine
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• 제8권2호
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• pp.171-177
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• 2008

Epigallocatechin 3-gallate (EGCG), one of the major catechins of tea, was isolated from the decaffeinated, crude methanolic extract of Indian green tea (Camellia sinensis L. O. Kuntze) using chromatographic techniques. EGCG was then screened for antidiarrhoeal activity against 30 strains (clinical isolates) of V. cholerae, which is a well known Gram negative bacillus functioning as the pathogen of cholera. V. cholerae strains like V. cholerae 69, 71, 83, 214, 978, 1021, 1315, 1347, 1348, 569B and ATCC 14033 were inhibited by EGCG at a concentration of $25\;{\mu}g/ml$ whereas V. cholerae 10, 522, 976 were even more sensitive, being inhibited at $10\;{\mu}g/ml$ level. However, V. cholerae DN 16, DN 26, 30, 42, 56, 58, 113, 117, 564, 593, 972 and ATCC 14035 were inhibited at $50\;{\mu}g/ml$ level of EGCG. Only four strains were inhibited at $100\;{\mu}g/ml$. In this study the isolated compound was found to be bacteriostatic in its mechanism of action. In the in vivo experiment using the rabbit ileal loop model two different dosages of EGCG ($500\;{\mu}g/ml$ and $1,000\;{\mu}g/ml$) were able to protect the animals when they were challenged with V. cholerae 569B in the ileum.

• 한국미생물·생명공학회지
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• 제10권2호
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• pp.73-78
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• 1982

전보에서 선정한 Streptococcus pyogenes 의 살균제, 항생물질 처리에 따른 적정 살균조건을 검토하여 다음과 같은 결자를 얻었다. 과산화수소 농도가 0.2%일 때는 생존균의 감소에 영향이 없었으나 0.4, 0.5, 0.8, 1%로 농도를 증가함에 따라 생존균의 감소가 급격하게 일어났으며 1 % 농도 처리시 10분만에 생존율은 0.5% 미만이었다. Erythromycin, tetracycline, cephalerin 각각의 MIC (Minimum inhibitory concentration) 는 0.78, 0.39, 3.125 $\mu\textrm{g}$/$m\ell$이었다.

• 한국식품영양과학회지
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• 제25권6호
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• pp.932-936
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• 1996

자숙가리비의 shelf-life를 연장하기 위하여 열처리하여 탈각한 가리비를 진공 및 질소가스 포장하여 $5^{\circ}C에$ 저장하면서 여러가지 화학적 및 미생물적 변화를 분석하였다. pH는 저장기간이 증가할수록 감소하였으며 진공 및 질소가스 포장은 저장 18일 이후의 급격 한 pH 감소를 억제하였다. 진공 및 질소가스 포장은 아미노태질소, TMA, VBN, TBA생성 및 미생물 생육 억제효과를 나타내었으며, 두 포장방법 사이에는 뚜렷한 효과 차이는 없었다. 진공 및 질소가스 포장은 $5^{\circ}C에$ 저장된 자숙가리비의 shelf-life를 대조구 30일에 비교하여 약 6일 정도 연장하였다.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.229-236
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• 1998

6-Substituted derivatives of 1-［(2-hydroxyethoxy)methyl］-6-(phenylthio)thymine (HEPT) were synthesized by introducing alkyl groups with the aid of chlorotrimethylsilane, and then purified ranging 40 to 81 % of yield. Because of their peculiar structures, we presumed that HEPT derivatives would contain extra biological activities other than their already known anti-human immunodeficiency viral (HIV -1) activities. In this study, we investigated the possible effects of the HEPT derivatives on bacterial growth and found their selective antibiotic activities against gram-positive strains. We could not observe the corresponding activity from a disc-zone test, but confirmed the activity by liquid cultivation. Since the growth rate of cells was easily recovered, the antibiotic function was suggested to be bacteriostatic. We also suggested that the intracellular fate of HEPT derivatives would be fast. A HEPT derivative f-3 was shown to synergize unidirectionally toward chloramphenicol (Chr). With 0.1 mM f-3, the Chr-directed growth-inhibitory curve appeared 4 hours earlier than found without the additive. Interestingly, from the data of SDS-polyacrylamide gel electrophoresis (PAGE), we found that a membrane-bound protein having a molecular weight of 70-kDa was overexpressed by f-3 in S. aureus.

• Advances in Traditional Medicine
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• 제6권2호
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• pp.126-133
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• 2006

The cardiovascular drug nifedipine exhibited significant in vitro and in vivo antibacterial activity against 331 strains of bacteria belonging to three Gram-positive and twelve Gram-negative genera. The minimum inhibitory concentration of the drug, as determined both by agar and broth dilution methods, was seen to range from $25\;-\;200\;{\mu}g/ml$ against most test bacteria, including several pathogenic ones, in the in vitro studies. Nifedipine was bacteriostatic in action. in vivo studies with this drug showed that it could offer statistically significant protection (P < 0.001) to mice challenged with a virulent bacterium. Therefore, nifedipine has the potential of an antibacterial agent, which may be developed after further pharmacological studies.

• 약학회지
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• 제57권2호
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• pp.95-100
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• 2013

This study was performed to analyze in vitro and in vivo activities of LCB01-0183, a new oxazolidinone, against clinical isolates of bacteria. In vitro antibacterial activity of LCB01-0183 was tested by the two fold agar dilution method. In vivo activity of LCB01-0183 was determined against systemic infections in mice. LCB01-0183 showed most potent activity among the test compounds against clinical isolates of Gram-positive bacteria. Furthermore, the protective activity of LCB01-0183 was very effective against systemic infections in mice by oral or subcutaneous administration. In time kill study, LCB01-0183 showed a bacteriostatic activity during 24 hours. LCB01-0183 had potent in vitro and in vivo activity against Gram-positive bacteria including drug-resistant strains.

• 한국축산식품학회지
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• 제38권6호
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• pp.1315-1321
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• 2018

Bacteriocin is ribosomally synthesized by bacteria and inhibits closely related species. In this study we aimed at isolating lactic acid bacteria producing bacteriocin presenting anti-staphylococcal activity. A Lactococcus lactis strain was isolated from kimchi for the purpose and identified by 16S rRNA gene sequencing. As preliminary tests, optimal culture conditions, stabilities against heat, solvents, and enzymes treatments, and type of action (bacteriostatic or bactericidal) of the bacteriocin were investigated. The optimal culture conditions for production of the bacteriocin were MRS broth medium and $25^{\circ}C$ and $30^{\circ}C$ culture temperatures. The bacteriocin was acidic and the activity was abolished by a protease treatment. Its stability was maintained at $100^{\circ}C$ for 15 min and under treatments of various organic solvents such as methanol, ethanol, acetone, acetonitrile, and chloroform. Finally, the bacteriocin showed bactericidal action against Staphylococcus aureus where 200 AU/mL of the bacteriocin decreased the viable cell count (CFU/mL) of S. aureus by 2.5 log scale, compared with a control (no bacteriocin added) after 4-h incubation.